Potash, or Pottasche, is a baking aid used in German baking recipes especially Lebkuchen (Gingerbread). It is also known as Potassium carbonate (K2C03). It is an alkaline salt (white powder) which reacts with water or an acid (fruit juice or sour milk) to create carbon dioxide, which gives baked goods a lift.
How to use
Use in doughs with high sugar content (honey) that stay flat.